Use of X-Bleed valve in case of Engine shutdown

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▪︎This content is Not an official document and does not represent the views of Airbus or any other aviation authority.

▪︎The information provided may be incorrect or misinterpreted and should not be relied upon for decision-making. 

▪︎Always refer to official documents and consult with a qualified aviation professional before making any decisions based on the information provided in this blog post.

▪︎The information provided in this blog post is based on personal study and review.

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An engine failure ECAM will lead to the associated ‘engine shutdown’ procedure.

 

Crossbleed , ENGINE SHUTDOWN PRCEDURE

This procedure directs the engine crossbleed to be shut if the engine fire pushbutton (pb-sw) is pressed,

 

 

and the crossbleed to be opened if wing anti-ice is off and the engine fire pushbutton is not pressed, provided performance permits.

 

If no obstacle constraints exist, the FCOM recommends opening the crossbleed. This is probably also related to the engine relight procedure.

 

 

 

In the engine relight procedure, the crossbleed needs to be opened. If the aircraft is outside the windmilling start envelope, the FADEC will open the start valve and use bleed air.

 

 

In the Simulator 

If the flight crew closes the crossbleed after judging the engine as damaged, sometimes in the simulator an ‘Engine Start Valve Fault’ ECAM appears, instructing to open the crossbleed.

 

This might be because the simulator instructor sets up a scenario with no engine damage, but the flight crew judged it as engine damage and pressed the engine fire pushbutton, which closed the crossbleed valve.

 

The simulator computer may still recognize the situation as non-damage, which could be why the ECAM instructs to open the crossbleed. I’m not sure if this happens in the real aircraft, but it does occur in the simulator.

 

 

APU BLEED when engine shutdown 

In case the engine fire pushbutton is pressed (due to engine fire or damage), the engine crossbleed needs to be in the shut position. The APU bleed can be used only if the engine fire pushbutton 2 is pressed. If engine fire pushbutton 1 is pressed, APU bleed cannot be used.

 

 

 

If the APU bleed is turned on, the crossbleed will open, and the engine bleeds will close. So, whether or not the APU bleed is used, in case of an engine relight, the crossbleed will be opened.

 

If there is no engine damage, it is better to open the crossbleed for an engine relight attempt. However, if there is engine damage, the crossbleed should remain shut, and the APU bleed can only be used if engine fire pushbutton 2 is pressed.